With only minor modification, existing operating municipal digesters can reduce waste going to landfill with biogas and nutrient concentrate capture.
An options review for modifying existing WWTP digester assets in New Zealand to add co-digestion of trade waste shows a number of facilities which can be modified before 2030. By 2050, this solution could process 70% of all WWTP biosolids and divert up to 650,000 t/annum waste from landfill (biosolids, grease trap, industrial waste, selected food waste).
The commercial drivers for the digester upgrades are better utilization of existing assets; recovery of nutrient concentrates and gaseous biofuel; WWTP operating cost offsets; PLUS deferred CAPEX investment for the asset owners.
Organics has recently developed a process which facilitates the recovery of ammonia from wastewater and digestates from municipal sludge, trade waste and primary industry residues. Pilot plants are currently being trialed at two UK facilities (Severn Trent Water and Northumbrian Water).
The presentation will center around ammonia recovery and its technical/commercial potential.